Network Load Balancer

Network Load Balancer (NLB) operates on the transport layer, the fourth layer of the OSI model, and is used to distribute incoming TCP and UDP traffic across multiple targets. NLB uses a single static IP address and is optimized to handle sudden and volatile traffic patterns.

Once a Network Load Balancer receives a request from a client, it tries to open a connection with a target from the target group on the port specified in the targets’ listener rule. The protocols Network Load Balancers support are TCP, TLS, UDP, and TCP_UDP. NLB supports zonal isolation, which means it was created for architectures residing in a single AZ. However, using multiple zones is recommended as it increases the availability of our applications.

Internet vs. internal facing load balancers

We can create internet and internal facing Network Load Balancers in the AWS Cloud. The internet-facing NLBs are used to route the traffic coming ...